Testis & paratestis
Germ cell tumors
Teratoma-neuroendocrine tumor
Author: Rafael E. Jimenez, M.D.
Last author update: 1 September 2012
Last staff update: 16 January 2023 (update in progress)
Copyright: 2002-2023, PathologyOutlines.com, Inc.
PubMed Search: carcinoid [title] well differentiated neuroendocrine tumor
Table of Contents
Definition / general | Terminology | Epidemiology | Etiology | Clinical features | Prognostic factors | Case reports | Treatment | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Positive stains | Negative stains | Electron microscopy description | Molecular / cytogenetics description | Differential diagnosisCite this page: Jimenez R. Teratoma-neuroendocrine tumor. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/testiscarcinoid.html. Accessed March 22nd, 2023.
Definition / general
- Low grade neuroendocrine carcinoma, similar to counterpart at other sites
- Usually monomorphic cells growing in solid nests, trabeculae or pseudoglands
Terminology
- Also called pure neuroendocrine carcinoma
- Previous called carcinoid tumor, well differentiated neuroendocrine tumor
Epidemiology
- Rare ( < 1% of testicular neoplasms), mean age 46 years
Etiology
- Carcinoid tumors are neuroendocrine tumors derived from enterochromaffin (Kulchitsky) cells that secrete serotonin and most commonly arise in GI and respiratory tracts
- In testis, presumed to be a monodermal teratoma, although 20% have other teratomatous elements
Clinical features
- Only 10% have clinical carcinoid syndrome
Prognostic factors
- Metastatic disease is associated with carcinoid syndrome, tumor size 7 cm or more (Cancer 1993;72:1726)
Case reports
- 12 year old boy with nodal metastases (J Pediatr Surg 2005;40:e19)
- 25 year old man with intratubular germ cell neoplasia in surrounding tissue (J Clin Pathol 2005;58:1331)
- 41 year old man with incidental tumor found at elective sterilization (J Androl 2004;25:338)
- 76 year old man with metastatic carcinoid tumor (Arch Pathol Lab Med 1981;105:515)
Treatment
- Excision; occasionally metastasizes
Gross description
- Solid, yellowish tan, well circumscribed
- Cysts reflect other teratomatous elements
Gross images
AFIP images
Solid, tan cut surface
Microscopic (histologic) description
- Islands of cells forming small acini; cords forming rosettes or sheets
- Cells have granular eosinophilic cytoplasm, round nuclei with granular chromatin
- Usually no intratubular germ cell neoplasia, no / minimal mitotic activity, usually minimal atypia or necrosis
Microscopic (histologic) images
AFIP images
Well defined acini and
solid islands of cells
separated by fibrous stroma
Eosinophilic cytoplasm and
round nuclei with coarsely
granular chromatin
Images hosted on other servers:
Insular pattern, chromogranin+
Intratubular germ cell neoplasia
Placental-like alkaline phosphatase
Testicular carcinoid tumor
Cytology description
- Isolated or sheets of tumor cells with granular cytoplasm, round nuclei, uniformly distributed fine chromatin
Positive stains
- Cytokeratin, chromogranin, synaptophysin, serotonin (Am J Clin Pathol 2003;120:182)
Electron microscopy description
- Neurosecretory granules
Molecular / cytogenetics description
- i(12p) (Clin Cancer Res 2008;14:1393)
Differential diagnosis
- Metastatic carcinoid to testis: usually bilateral, multifocal, vascular invasion, case report of metastasis to scrotum at Am J Clin Pathol 1991;96:664
- Sertoli cell tumor: lacks prominent cytoplasmic granularity and coarse chromatin; inhibin+
